U.S. patent application number 16/321268 was filed with the patent office on 2019-05-30 for device for protecting an optical sensor and driving aid system comprising an optical sensor.
This patent application is currently assigned to Valeo Systemes d'Essuyage. The applicant listed for this patent is Valeo Systemes d'Essuyage. Invention is credited to Frederic Bretagnol, Giuseppe Grasso, Gregory Kolanowski, Marcel Trebouet.
Application Number | 20190162953 16/321268 |
Document ID | / |
Family ID | 57121360 |
Filed Date | 2019-05-30 |
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United States Patent
Application |
20190162953 |
Kind Code |
A1 |
Bretagnol; Frederic ; et
al. |
May 30, 2019 |
DEVICE FOR PROTECTING AN OPTICAL SENSOR AND DRIVING AID SYSTEM
COMPRISING AN OPTICAL SENSOR
Abstract
The present invention relates to a device 3 for protecting an
optical sensor 13 for an automotive vehicle that is intended to be
attached to the optical sensor, characterized in that the device
includes: -a transparent optical element 9 exhibiting rotational
symmetry and being rotatably mounted about an axis of rotation,
configured to be positioned upstream of the optical sensor 13 so
that the axis of rotation of the optical element 9 is merged with
the optical axis 15 of the optical sensor 13; and -an actuator 5
that is coupled to the optical element 9 so as to rotate the
optical element 9 in order to allow soiling to be removed by a
centrifugal effect.
Inventors: |
Bretagnol; Frederic;
(Issoire, FR) ; Grasso; Giuseppe; (Issoire,
FR) ; Kolanowski; Gregory; (Issoire, FR) ;
Trebouet; Marcel; (Le Mesnil Saint Denis, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Valeo Systemes d'Essuyage |
Le Mesnil Saint Denis |
|
FR |
|
|
Assignee: |
Valeo Systemes d'Essuyage
Le Mesnil Saint Denis
FR
|
Family ID: |
57121360 |
Appl. No.: |
16/321268 |
Filed: |
July 18, 2017 |
PCT Filed: |
July 18, 2017 |
PCT NO: |
PCT/EP2017/068138 |
371 Date: |
January 28, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60R 2300/10 20130101;
B60R 2300/8093 20130101; B60S 1/56 20130101; B60R 2300/804
20130101; B08B 17/06 20130101; G02B 27/0006 20130101; B60R 2300/806
20130101; B08B 3/041 20130101 |
International
Class: |
G02B 27/00 20060101
G02B027/00; B60S 1/56 20060101 B60S001/56; B08B 17/06 20060101
B08B017/06; B08B 3/04 20060101 B08B003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2016 |
FR |
1657320 |
Claims
1. A device for protecting an optical sensor for motor vehicles,
the device being fixed to the optical sensor and comprising: a
transparent optical element having a symmetry of revolution and
mounted rotatably around an axis of rotation, the optical element
being configured to be arranged upstream of the optical sensor so
that the axis of rotation of the optical element coincides with the
optical axis of the optical sensor; and an actuator coupled to the
optical element for making the optical element rotate, to enable
soiling to be removed by a centrifugal effect.
2. The device for protecting an optical sensor as claimed in claim
1, wherein the actuator comprises an electric motor for driving the
optical element.
3. The device for protecting an optical sensor as claimed in claim
2, wherein said electric motor is configured to make the optical
element rotate at a speed of between 7000 and 15000 r.p.m.
4. The device for protecting an optical sensor as claimed in claim
1, wherein the actuator is coupled to the optical element by
coupling means selected from the group consisting of: a belt,
gearing, a resilient drive cylinder, and a roller.
5. The device for protecting an optical sensor as claimed in claim
1, wherein the optical element has an outer surface having at least
one of the properties selected from the group consisting of:
hydrophobic, photocatalytic, superhydrophobic, oleophobic,
hydrophilic, and superbydrophilic.
6. The device for protecting an optical sensor as claimed in claim
1, wherein the optical element is formed by an outer lens of the
objective lens of the optical sensor.
7. The device for protecting an optical sensor as claimed in claim
1, wherein the optical element is separate from the objective lens
of the optical sensor.
8. The device for protecting an optical sensor as claimed in claim
7, wherein the optical element is connected to a fixing frame
configured to receive the optical sensor.
9. The device for protecting an optical sensor as claimed in claim
1, wherein the optical element is flat.
10. The device for protecting an optical sensor as claimed in claim
1, wherein the optical element is convex.
11. The device for protecting an optical sensor as claimed in claim
1, further comprising at least one nozzle for projecting a fluid
onto the optical element.
12. The device for protecting an optical sensor as claimed in claim
1, further comprising at least one bearing configured to enable the
optical element rotate relative to the optical sensor.
13. A driving aid system, comprising: an optical sensor: a device
for protecting the optical sensor as claimed in claim 1; and an
electronic control unit configured to activate the actuator in
order to make the optical element rotate.
14. The driving aid system as claimed in claim 13, wherein the
electronic control unit is configured to control the actuator so as
to adapt the rotation speed of the optical element according to the
speed of movement of the motor vehicle.
15. The driving aid system as claimed in claim 14, wherein the
actuator is configured to reduce the rotation speed of the optical
element when the speed of the vehicle increases.
16. The driving aid system as claimed in claim 13, wherein the
electronic control unit is configured to actuate the projection of
at least one fluid onto the optical element when the optical sensor
detects the presence of soiling in its field of view.
17. The driving aid system as claimed in claim 16, wherein the
electronic control unit is configured to actuate the projection of
two different fluids, such as cleaning liquid and compressed air,
consecutively.
18. The driving aid system as claimed in claim 13, wherein the
protection device comprises a capacitive proximity sensor connected
to the electronic control unit and configured to detect the
approach of another object in the proximity of the optical element,
and to enable the electronic control unit to command the automatic
stopping of the actuator, in order lo halt the rotation of the
optical element when another object approaches.
Description
[0001] The present invention relates to the field of driver
assistance, and notably to driving aid systems fitted in some
vehicles, the driving aid system possibly comprising an optical
sensor, for example a camera comprising a lens. More particularly,
the invention concerns a device for protecting such an optical
sensor, the optical sensor possibly being placed inside a bodywork
part of a motor vehicle, for example.
[0002] Front, rear or side view cameras are fitted to many motor
vehicles at the present time. Notably, such cameras form part of
driving aid systems such as parking aid systems or line crossing
detection systems.
[0003] There are cameras that are fitted inside the passenger
compartment of a vehicle for assistance in parking. These cameras
are well protected from weather hazards and from soiling caused by
organic or mineral contaminants. However, the angle of view for
such cameras fitted inside the passenger compartment is not
optimal, particularly for a parking aid, since they do not provide
a view of obstacles located near the rear of the vehicle, for
example.
[0004] It is therefore preferable to install these driving aid
systems, and notably their cameras, on the outside of vehicles at
various locations, depending on their intended use. In such a case,
the driving aid system, and particularly the camera of such a
system, is highly exposed to weather hazards and to projections of
mineral or organic soiling that may reduce its effectiveness or
even render it inoperative.
[0005] To counteract the deposition of soiling on the driving aid
system, there is a known way of arranging a device for cleaning the
optical component of the camera, usually a cleaning liquid spray
located near the camera, for eliminating contaminants that have
been deposited over time.
[0006] However, the use of these sprays increases the operating
costs of such a driving aid system, because they require the use of
rather large amounts of cleaning liquid.
[0007] On the other hand, the optical component of the camera,
usually consisting of a lens, is a relatively fragile device. It
must therefore be protected against projections that might damage
it. Consequently, such cameras are commonly housed in protective
casings comprising a protective window arranged facing the lens.
However, the cleaning of the lens, or of the window in the casing
that protects it, is of major importance for the correct operation
of the camera.
[0008] The document FR2841488 discloses such a casing enclosing an
optical sensor with means for cleaning the casing, composed of a
spray and means for causing the vibration of a window facing the
camera.
[0009] However, this device may be too bulky in some cases, notably
when it is to be fitted on the vehicle's number plate, on the front
or rear bumpers, or on the rear-view mirrors. Furthermore, this
device only allows the cleaning liquid to flow over the window, and
its effectiveness for stubborn and encrusted soiling may be limited
in spite of the vibration of the glazing and the catalytic
treatment that the latter has undergone.
[0010] To enable this driving aid system to be fitted at any useful
point on the vehicle, it is possible to dispense with the
protective casing comprising cleaning means as described above. In
this case, a smaller protective casing, adapted to the size of the
optical sensor, must be provided to protect the sensor. It is also
necessary to provide means for cleaning the optical component of
the driving aid system in order for it to exhibit good operating
conditions, for example the capture of clear and clean images,
which appears to be difficult if the optical component of such a
system is contaminated by organic or mineral contaminants or by
traces of water. The document U.S. Pat. No. 8,899,781 discloses
such a protective casing, which is designed to receive an optical
sensor such as a camera for a motor vehicle, and is designed to be
installed on the outside of the vehicle. The protective casing
described in this document comprises an outer fixed cover for
protecting the camera lens, and a piezoelectric transducer for
causing the assembly to vibrate and thus allowing soiling to fall
from the cover.
[0011] However, such a vibration of the assembly greatly increases
the risks of fracture and/or cracking of the material from which
the camera lens is made, or of the cover sealing the protective
casing in which the camera is located. It is therefore necessary to
use glasses or plastics which are highly resistant to impact and
vibration, and are free of manufacturing flaws, for making these
elements. This constraint increases the manufacturing costs of such
systems, since glasses and plastics capable of withstanding these
mechanical stresses are usually expensive, and the necessary
freedom from flaws may increase the rejection rate of components.
Moreover, the vibrations of the assembly may damage the internal
system of the camera, particularly its electronic components.
[0012] For the purpose of installing the driving aid system on the
outside of the vehicle without the need for a protective casing,
there is a known way of installing these systems inside certain
bodywork parts, such as the rear-view mirrors or the front or rear
bumpers, so that they project slightly from these bodywork parts.
The camera lens is usually covered with a protective cover to
provide it with protection against projections and/or impact. A
cleaning system must also be provided for such installations. The
document US2012/0000024 discloses a device for protecting an
optical sensor installed in this way. This protection device
comprises a transparent disc mounted rotationally in a casing. The
casing comprises cleaning pads and a heating element for de-icing
the transparent disc. The outer casing may also comprise a wiper
blade for removing solid soiling that may be deposited on the
rotating disc. The rotating disc fitted to this protection device
has a larger diameter than the camera lens, usually at least twice
as large, its axis of rotation being offset from the optical axis
of the camera.
[0013] However, such a protection device does not enable the
optical sensor to have a wide field of vision, because the optical
sensor is located behind this casing. Thus the thickness of the
casing makes it difficult to obtain a wide field of vision for such
an optical sensor. For optimal operation, such a driving aid system
must provide a wide field of vision. Moreover, it may be difficult
to clean the pads, because they may become clogged and/or moldy as
a result of the humidity, the temperature, and any residual soiling
deposited on them. Furthermore, the transparent disc may have
micro-scratches caused by small residues that may become jammed
between the wiper and the transparent disc, and this would impede
the correct operation of the optical sensor installed in such a
casing, since these micro-scratches may harm the quality of the
image.
[0014] Additionally, the document DE102008027430 discloses a device
for protecting an optical sensor using a rotating cover which has
hydrophobic properties and/or enables the adhesion of soiling to
the cover to be limited, this cover being designed to be made to
rotate by an electric motor. The protection device also comprises a
nozzle for projecting a cleaning liquid, a washing element which
may be a wiper blade, and a drying element.
[0015] However, such a protection device may be noisy if the cover
is made to rotate at high speeds, notably as a result of the
friction between the cover and the wiper blade. Moreover, the
cleaning and drying elements may be subject to premature wear due
to the continuous rotation of the cover at a rather high speed.
Additionally, such a protection device may be rather bulky to
install, since the rotating cover is offset relative to the optical
sensor and has a diameter at least twice as great as the diameter
of the optical component of the optical sensor that it protects and
whose correct operability it ensures. It is also possible for
micro-scratches to appear on the cover if solid particles are
deposited between the wiper and the rotating cover. This may cause
the field of view and the quality of the images captured by the
optical sensor to be affected as before. Finally, the use of such a
protection system makes it impossible to have a wide field of
vision, because of the arrangement of the optical sensor within a
casing carrying the cover, without creating a projection from this
casing.
[0016] The present invention aims to overcome, at least partially,
the aforementioned drawbacks of the prior art, by proposing a
device, projecting from the sensor, for protecting the optical
component of an optical sensor, such as the lens of a camera.
[0017] Another object of the present invention is to propose a
protection device for fast and effective cleaning of the lens.
[0018] The present invention also has the object of proposing a
protection device for reducing the amounts of cleaning fluid
required to clean the optical component.
[0019] For this purpose, the invention proposes a device for
protecting an optical sensor for motor vehicles which is designed
to be fixed to the optical sensor, characterized in that the device
comprises: [0020] a transparent optical element having a symmetry
of revolution and mounted rotatably around an axis of rotation, the
optical element being configured to be arranged upstream of the
optical sensor so that the axis of rotation of the optical element
coincides with the optical axis of the optical sensor, and [0021]
an actuator coupled to the optical element for making the optical
element rotate, enabling soiling to be removed by a centrifugal
effect.
[0022] Thus the protection device may be installed on an optical
sensor to be installed inside a bodywork part of the vehicle, or
alternatively on the outside of the vehicle, while allowing the
optical sensor to retain a wide field of vision.
[0023] The term "soiling" is taken to mean drops of water as well
as organic or mineral contaminants.
[0024] In rainy or dry weather, there is a risk that soiling may be
deposited on the optical element and may impede the correct
operation of the optical sensor. When the optical element is made
to rotate at a relatively high speed by means of the actuator, any
soiling is ejected by a centrifugal effect. This is because the
work of the centrifugal force created in this way is greater than
the force of adhesion of the soiling to the optical element. Thus
the optical sensor continues to be operable in the correct way, and
its clogging is limited, regardless of the weather conditions. Thus
the driving aid system maintains a good level of visibility.
[0025] The device for protecting the optical sensor according to
the invention may also have one or more of the following
characteristics, considered individually or in combination:
[0026] The actuator comprises an electric motor, such as a
brushless motor, for driving the optical element.
[0027] The electric motor is configured to make the optical dement
rotate at a speed of between 1000 and 50000 r.p.m., preferably
between 5000 and 20000 r.p.m., and even more preferably between
7000 and 15000 r.p.m.
[0028] The actuator is coupled to the optical element by coupling
means chosen from the following list: a belt, gearing, a resilient
drive cylinder, and a roller.
[0029] The optical element has an outer surface having at least one
of the properties chosen from the following list: hydrophobic,
photocatalytic, superhydrophobic, oleophobic, hydrophilic, and
superhydrophilic.
[0030] According to a variant, the optical element is formed by an
outer lens of the objective lens of the optical sensor.
[0031] According to another variant, the optical element is
separate from the objective lens of the optical sensor.
[0032] According to this second variant, the optical element is
connected to a fixing frame configured to receive the optical
sensor.
[0033] According to this second variant, the optical element may be
flat.
[0034] According to this second variant, the optical element may be
convex.
[0035] The device for protecting the optical sensor comprises at
least one nozzle for projecting a fluid onto the optical
element.
[0036] According to a variant, the fluid is compressed air.
[0037] According to another variant, the fluid is a cleaning
liquid.
[0038] The device for protecting the optical sensor comprises at
least one bearing configured for the rotation of the optical
element relative to the optical sensor.
[0039] The invention also proposes a driving aid system comprising
an optical sensor, said driving aid system further comprising a
device for protecting the optical sensor as described above, and an
electronic control unit configured to activate the actuator in
order to make the optical element rotate.
[0040] Thus the driving aid system comprising at least one camera
may be installed on any bodywork part and can provide a wide angle
of view. Furthermore, the field of view of the camera cannot be
adversely affected by the presence of soiling. The operation of the
optical sensor forming this driving aid system is therefore
improved.
[0041] The driving aid system may also have one or more of the
following characteristics, considered individually or in
combination:
[0042] According to a variant, the electronic control unit is
configured to activate the actuator so as to make the optical
element rotate constantly during the operation of the vehicle.
[0043] According to another variant, the electronic control unit is
configured to activate the actuator so as to make the optical
element rotate intermittently during the operation of the
vehicle.
[0044] The electronic control unit is configured to control the
actuator so as to adapt the rotation speed of the optical element
according to the speed of movement of the motor vehicle.
[0045] The actuator is configured to reduce the rotation speed of
the optical element as the speed of the vehicle increases, when the
optical element is installed at the front of the vehicle.
[0046] According to a variant, the electronic control unit is
configured to actuate the projection of at least one fluid, such as
cleaning liquid or compressed air, onto the optical element when
the optical sensor detects the presence of soiling in its field of
view.
[0047] According to another variant, the electronic control unit is
configured to actuate the projection of two different fluids, such
as cleaning liquid and compressed air, consecutively.
[0048] The protection device comprises a capacitive proximity
sensor connected to the electronic control unit and configured to
detect the approach of another object in the proximity of the
optical element, and to enable the electronic control unit to
command the automatic stopping of the actuator, in order to halt
the rotation of the optical element if another object
approaches.
[0049] Thus, by consecutively rotating the optical element and
projecting fluid onto it, the optical element can be cleaned
effectively and the operability of the optical sensor can be good,
regardless of the weather conditions. In fact, stubborn soiling may
be deposited on the optical element when the vehicle is parked. By
using cleaning and/or compressed air in addition to the centrifugal
effect, this stubborn soiling is removed from the optical element.
By combining fluid projection with the rotation of the optical
element, therefore, a cleaning system for the optical element of
the optical sensor can be created.
[0050] Other advantages and features of the invention will be
apparent from a perusal of the description of the invention and the
attached drawings, in which:
[0051] FIG. 1 is a perspective view of a longitudinal section
through the driving aid system according to a first embodiment,
[0052] FIG. 2 is a schematic front view of the driving aid system
installed in a bodywork part of the vehicle,
[0053] FIG. 3 is a schematic rear view of the driving aid system
installed in a bodywork part of the vehicle,
[0054] FIG. 4 is a schematic view of the device for protecting the
optical sensor according to a particular embodiment,
[0055] FIG. 5 is a schematic longitudinal view of the driving aid
system according to the particular embodiment of FIG. 4,
[0056] FIG. 6 is a schematic perspective view of the driving aid
system according to the particular embodiment of FIG. 4, and
[0057] FIG. 7 is a schematic view of the driving aid system
according to another embodiment.
[0058] In these figures, identical elements bear the same reference
numerals.
[0059] The following embodiments are examples. Although the
description refers to one or more embodiments, this does not
necessarily mean that each reference concerns the same embodiment,
or that the characteristics are applicable to a single embodiment
only. Simple characteristics of different embodiments may also be
combined or interchanged to provide other embodiments.
[0060] In the following description, reference is made to a first
and a second nozzle. This is a simple form of indexing for the
purpose of differentiating and designating elements which are
similar but not identical. This indexing does not imply that any
element takes priority over another, and such designations may
easily be interchanged without departing from the scope of the
present description. Furthermore, this indexing does not imply any
ordering. In time for example, for the purpose of understanding the
operation of the device for cleaning the optical sensor.
[0061] In the following description, "upstream" is defined by the
direction of the light radiation, that is to say from the outside
toward the inside of the optical sensor. Additionally, in the
following description, "convex" is taken to mean "curved toward the
outside of the optical sensor".
[0062] In the following description, "soiling" is taken to mean
drops of water as well as traces of water, organic or mineral
contaminants, or a combination of these different elements.
[0063] With reference to FIG. 1, the invention concerns a driving
aid system 1 which is, notably, installed in a bodywork part 2 of a
motor vehicle. The driving aid system comprises a device 3 for
protecting an optical sensor 13 for a motor vehicle, such as a
camera having an optical component 14, a lens for example. The
protection device 3 according to this embodiment is designed to be
fixed to the optical sensor 13.
[0064] The protection device 3 further comprises a transparent
optical element 9 and an actuator 5.
[0065] The optical element 9 has a symmetry of revolution and is
mounted rotatably around an axis of rotation which coincides with
the optical axis 15 of the optical sensor 13, the axis of
revolution of the optical element 9 also being the axis of rotation
of the latter. According to this embodiment, the optical element 9
is configured to be arranged upstream of the optical sensor 13 to
protect the latter from soiling.
[0066] The actuator 5 is coupled to the optical element 9 with the
aid of coupling means 7 for making the optical element 9 rotate, so
as to enable soiling to be removed by a centrifugal effect. This is
because the centrifugal force to which the soiling will be
subjected as a result of the rotation of the optical element 9 is
greater than the adhesion of this soiling to the optical element 9.
Thus the soiling is ejected from the optical element 9 and does not
interfere with the field of view of the optical sensor 13.
[0067] According to this particular embodiment, the actuator 5 of
the protection device 3 is designed to be fixed to the optical
sensor 13 by means of a mounting 17.
[0068] According to this embodiment, the actuator 5 comprises an
electric motor, more particularly a brushless motor, for driving
the optical element 9. The electric motor forming the actuator 5 is
configured to make the optical element 9 rotate at a speed of
between 1000 and 50000 r.p.m., preferably between 5000 and 20000
r.p.m., and even more preferably between 7000 and 15000 r.p.m. Such
rotation speeds are sufficient for removing the soiling deposited
on the optical element 9 by a centrifugal effect, thus keeping the
optical component 14 of the optical sensor 13 in a state of
cleanliness which is ideal for ensuring the improved operation of
the driving aid system 1.
[0069] To ensure that the operation of the driving aid system 1 is
improved, it is also necessary to limit the possible adhesion of
organic or mineral contaminants, as well as the presence of traces
of water on the optical element 9. For this purpose, the optical
element 9 has an outer surface having one or more of the following
properties: hydrophobic, photocatalytic, superhydrophobic,
oleophobic, hydrophilic, or superhydrophilic, or any other surface
treatment for reducing the adhesion of soiling. Because of the
hydrophobic properties of the outer surface of the optical element
9, the water can only flow over this element without leaving any
traces, since the water will be unable to adhere to it. Moreover,
the photocatalytic properties of the outer surface of the optical
element 9 limit the possible adhesion of organic or mineral
contaminants to it. Thus the composition of the optical element 9
makes it possible to limit the presence of traces that may
adversely affect the correct operation of the driving aid system
1.
[0070] Advantageously, a liquid solution (such as Rain-X.RTM., for
example) may be deposited (periodically and manually) on the outer
surface of the optical element 9 to form a hydrophobic film.
[0071] Optionally, a demisting treatment may be applied to the
inner surface of the optical element 9 to prevent any phenomenon of
condensation between the outer lens of the optical component 14 and
the inner surface of the optical element 9.
[0072] According to the embodiment described here, the optical
element 9 is positioned facing, and more precisely upstream of, the
optical component 14 of the optical sensor 13, being centered
relative to the optical component and covering the whole surface
area of this lens. Thus, the camera lens is protected from any
projections of organic or mineral contaminants or water that might
damage it. Additionally, the treatments carried out on the optical
element 9 provide improved operation of this camera.
[0073] According to the embodiment described here, the optical
element 9 has a similar diameter to that of the optical component
14 of the optical sensor 13. Thus the protection device 3 may
easily be installed on any type of optical sensor 13, since its
size is adapted to that of the optical sensor 13.
[0074] According to the particular embodiment of FIG. 1, the
optical element 9 is separate from the optical sensor 13.
Additionally, the optical element 9 is positioned upstream of the
optical component 14 of the optical sensor 13.
[0075] According to the embodiment of FIG. 1, the optical element 9
may, for example, be a protective glass. The optical element 9 is
designed to protect the optical component 14 of the optical sensor
13 from any projections of solid debris that might damage this
optical component 14. According to this embodiment, the optical
element 9 which is separate from the optical sensor 13 is convex.
However, the optical element 9 which is separate from the optical
sensor 13 may, according to another embodiment not shown here, be
flat.
[0076] According to another embodiment not shown here, the optical
element 9 may be formed by an outer lens of the optical component
14 of the optical sensor 13. In such a case, the optical sensor 13
comprises an integrated actuator 5 for making the optical element 9
rotate. In this case, the optical element 9 is mounted rotatably on
the optical sensor 13, for example with the aid of at least one
bearing 11 positioned on a fixed element of the optical sensor 13.
By way of example, in this case the fixed element of the optical
sensor 13 may be made in the form of a ring integrated into the
optical sensor 13.
[0077] According to the particular embodiment described here, and
in a non-limiting way, the means 7 for coupling the actuator 5 and
the optical element 9 consist of a belt.
[0078] Alternatively, the coupling element 7 may be gearing, a
resilient drive cylinder, or a roller, as shown in FIG. 7.
[0079] According to another embodiment not shown here, the optical
element may be made to rotate with the aid of a magnetic system
comprising two complementary elements, carried by the bearing 11 on
the one hand and by the optical element 9 on the other hand.
[0080] Advantageously, according to this embodiment, there is no
contact between the various parts which make the optical element 9
rotate. Thus the wear of the coupling element 7 may be limited.
[0081] According to the embodiment shown in FIG. 1, the protection
device 3 comprises at least one bearing 11, or rotary mounting,
configured for making the optical element 9 rotate relative to the
optical sensor 13. The inner ring of the bearing 11 is in contact
with en outer surface of the optical sensor 13, and the outer ring
is in contact with the optical element 9, which is in contact with
the coupling element 7. According to a variant embodiment, the
bearing 11 is arranged between the optical element 9 and a fixed
ring 18 integrated into the protection device 3 and configured to
receive the objective lens of the optical sensor 13. This fixed
ring 18 has an opening of sufficient diameter to allow the lens 14
of the optical sensor 13 to pass through the ring 18 and to allow
the objective lens of the optical sensor 13 to bear on the inside.
The bearing 11 is configured for making the optical element 9
rotate relative to the fixed ring 18 and therefore relative to the
optical sensor 13 when the latter is fitted with the protection
device 3. According to this particular embodiment, the protection
device 3 comprises a bearing 11, which may be a ball bearing, for
example.
[0082] In operation, the actuator 5 makes the optical element 9
rotate relative to the optical sensor 13, using the coupling means
7. This rotation is possible because of the presence of the bearing
11.
[0083] With reference to FIG. 1, the driving aid system 1 projects
from an opening located in a bodywork part 2. Thus the optical
component 14 and the optical element 9 project from this opening
and allow the driving aid system 1 to have a wide field of vision
while maintaining good operating conditions and effective
protection of the optical component 14, because of the protection
device 3 described above.
[0084] With reference to FIGS. 2 and 3, the driving aid system 1 is
shown as being installed inside a bodywork part 2 of a motor
vehicle.
[0085] With reference to FIGS. 2 and 3, the driving aid system 1 is
fixed inside the bodywork part 2 by any method known to those
skilled in the art, for example a clip system, a screw system, or
an adhesive system.
[0086] In FIG. 2, the arrow 20 shows the direction of rotation of
the optical element 9. In this case, the direction of rotation is
clockwise. However, this rotation could take place in the
anti-clockwise direction in another embodiment not shown here.
[0087] The driving aid system 1 comprises at least one nozzle 22
for projecting a fluid onto the optical element 9. According to the
embodiment described here, the driving aid system 1 comprises a
nozzle 22 for projecting a fluid onto the optical element 9.
[0088] This nozzle 22 is located, in this representation and in a
non-limiting way, above the optical element 9. However, according
to other embodiments not shown here, the nozzle 22 may be located
anywhere in the proximity of the optical dement 9.
[0089] The fluid projected by the nozzle 22 may be compressed air
or a cleaning liquid, to clean the optical dement 9 if the rotation
of the latter is insufficient to remove the various types of
soiling deposited on it. Alternatively, the projection of fluid may
be used in addition to the rotation of the optical dement 9 to
improve the state of cleanliness of this element.
[0090] On the other hand, according to other embodiments not shown
here, the protection device 3 may comprise a plurality of nozzles.
The protection device 3 may, for example, comprise a first nozzle
22 configured to project a first fluid such as cleaning liquid, and
a second nozzle configured to project a second fluid such as
compressed air, onto the optical dement 9.
[0091] According to the embodiment of FIG. 2, the nozzle is
connected to the cleaning liquid distribution system of the
vehicle.
[0092] According to another embodiment not shown here, the
protection device 3 may comprise its own dedicated reservoir for
cleaning liquid. In this case, this driving aid system 1 may be
installed relatively easily inside any bodywork part 2 of the motor
vehicle, for example the front or rear bumpers, or alternatively
the rear-view mirrors, without the need for a lengthy and complex
initial design process at the vehicle level for connecting the
protection device 3 to the cleaning liquid system of the vehicle in
order to supply the nozzle 22. In this configuration, this
protection device 3 may also be installed easily on any optical
sensor 13 located on the outside of the vehicle.
[0093] With reference to FIG. 4, the protection device 3 shown here
is designed to receive an optical sensor 13 as shown in FIGS. 5 and
6, to form the driving aid system 1.
[0094] According to the embodiment of FIG. 4, the optical element 9
is connected to a mounting, made in the form of a fixing frame 30
for example, configured to receive the optical sensor 13. For this
purpose, an opening is provided in the fixing frame 30. This
opening is configured to receive the optical sensor 13.
[0095] According to an embodiment not shown here, the fixing frame
30 may have adjusting means such that the opening can be adapted to
different camera casings of different sizes.
[0096] According to the embodiment of FIG. 4, the protection device
3 comprises straps 36 which are fixed to the fixing frame 30, for
connecting the fixing frame 30 to the optical element 9. These
straps 36 are, for example, connected to a bearing plate 38 of
substantially circular shape, as shown in FIG. 4, and configured so
that the objective lens of the optical sensor 13 bears on it, as
shown in FIGS. 5 and 6. This bearing plate 38 may carry the fixed
ring 18, the bearing 11 and the optical element 9. According to
this embodiment, the actuator 5 is positioned in contact with the
optical element 9.
[0097] According to another embodiment not shown here, the straps
36 may also be adjustable, or resilient, so that they can be
adapted to any type of optical sensor 13.
[0098] According to the embodiment of FIGS. 5 and 6, the optical
component 14 of the optical sensor 13 is in contact with the
bearing plate 38 which carries the fixed ring 18, the bearing 11,
the actuator 5 and the optical element 9. Thus the optical
component 14 is protected from any solid projection that might
damage it.
[0099] According to another embodiment not shown here, the fixed
ring 18 and the bearing plate 38 may be the same component.
[0100] According to the particular embodiment of FIGS. 4 to 6, the
actuator 5 is supplied with electricity by a power supply 34
connected to the main electrical circuit of the vehicle.
[0101] FIG. 7 shows an embodiment which is an alternative to FIGS.
4 to 6. According to this alternative, the driving aid system
comprises a block 40, to be installed inside a bodywork part, on
which block the protection device 3 is fixed. The block 40
comprises a housing 42 configured to receive the optical sensor 13,
the optical element 9 being positioned at an opening in the housing
42 for the passage of the optical component 14 of the optical
sensor 13. The block 40 also comprises holes 44 for fixing this
block 40 inside a bodywork part. According to the embodiment shown
in FIG. 7, the block 40 comprises four holes 44.
[0102] Additionally, the coupling element 7 may comprise a ring
having a friction coefficient chosen to be high enough to transmit
the rotary movement of the actuator 5 to the optical element 9, in
the manner of a roller, for example.
[0103] According to this particular embodiment, the motor providing
the movement of the actuator 5 is positioned inside the block
40.
[0104] According to another embodiment not shown here, the motor
providing the movement of the actuator 5 may be positioned outside
the block 40.
[0105] Additionally, when the block 40 has been installed inside
the bodywork part, the optical component 14 of the optical sensor
13 and the optical element 9 project from an opening present in the
bodywork part, in a similar way to that described with reference to
FIGS. 1 and 2.
[0106] According to a particular embodiment not shown here, the
block 40 is directly connected to the electrical system of the
vehicle to supply the actuator 5.
[0107] According to another particular embodiment not shown here,
the block 40 may comprise at least one plug for connecting the
optical sensor 13 inside the housing 42. This plug may be used to
supply electricity to the optical sensor 13 and to transmit the
images captured by the latter.
[0108] The driving aid system 1 therefore comprises an optical
sensor 13 comprising a protection device 3 as described above, and
an electronic control unit, not shown here, which is notably
configured to activate the actuator 5 in order to make the optical
element 9 rotate.
[0109] According to the embodiment described here, the actuator 5
is activated by the electronic control unit in such a way that the
optical element 9 is made to rotate constantly during the operation
of the vehicle.
[0110] According to another embodiment, the electronic control unit
is configured to activate the actuator 5 so as to make the optical
element 9 rotate intermittently during the operation of the
vehicle. According to this embodiment, the electronic control unit
may, for example, cause the actuator 5 to be started when the user
of the vehicle uses a function of the vehicle which requires the
operation of the optical sensor 13, for example if he engages
reverse gear when the driving aid system 1 is installed to provide
a view from the rear of the vehicle to facilitate its parking.
[0111] Advantageously, the electronic control unit is configured to
control the actuator 5 so as to adapt the rotation speed of the
optical element 9 according to the speed of movement of the motor
vehicle. This is because the soiling is removed from the optical
element 9 by the effect of the centrifugal force created by the
rotation of this optical element 9, possibly in combination with
the friction created by the movement of the vehicle, particularly
when the driving aid system 1 is located at the front of the
vehicle. Thus, as the speed of movement of the vehicle increases,
it becomes less necessary for the rotation speed of the optical
element 9 to be high in order to maintain a good state of
cleanliness of the optical element 9, resulting in improved
operation of the optical sensor 13. Thus the electronic control
unit will act on the actuator 5 so that it reduces the rotation
speed of the optical element 9 as the speed of the vehicle
increases, notably when the optical element 9 is installed at the
front of the vehicle.
[0112] According to a particular embodiment, the electronic control
unit is configured to make the rotation speed of the optical
element 9 vary. This variation of the rotation speed may result in
a change of the direction of rotation of the optical element 9.
Advantageously, the electronic control unit modifies the direction
of rotation of the optical element 9 several times in the course of
a fairly brief time interval. This change in the direction of
rotation promotes the appearance of acceleration phenomena, and can
effectively remove the small water drops located substantially in
the center of the optical element 9, for example. This is because
the variation in the direction of rotation of the optical element 9
subjects the soiling to acceleration in the opposite direction to
that of the movement of the soiling, thereby facilitating its loss
of adhesion to the optical element 9 and consequently its ejection
from it.
[0113] Alternatively or additionally, the electronic control unit
is controlled so as to make the rotation speed of the optical
element 9 vary in order to create acceleration which promotes the
detachment of the soiling located on the optical element 9.
[0114] During the operation of the protection device 3, the
electronic control unit is configured to actuate the projection of
at least one fluid, such as cleaning liquid or compressed air, onto
the optical element 9, using the nozzle 22, when the optical sensor
13 detects the presence of soiling in its field of view, for
example.
[0115] According to a particular embodiment, the electronic control
unit is configured to actuate the projection of compressed air onto
the optical element 9 when the vehicle is stationary or when it is
moving slowly, that is to say at a speed of less than 15 km/h, for
example. This is because, in such a case, the aerodynamic forces
are too weak to be coupled effectively with the centrifugal force
of the rotation of the optical element 9 to remove the drops of
water and/or the soiling that may be deposited on the optical
element 9. Moreover, at low speed or when the vehicle is
stationary, the small drops of water located at the center or near
the center of the optical element 9 may be difficult to remove,
because the rotation speed of the center of the optical element 9
may be too low to eject them. Advantageously, the projection of
compressed air onto the optical element 9 can compensate for the
absence of aerodynamic forces when the vehicle is moving slowly or
when it is stationary.
[0116] According to another embodiment, the electronic control unit
may be configured to actuate the projection of cleaning liquid
and/or compressed air after a certain period.
[0117] According to yet another embodiment, the electronic control
unit may be configured to actuate the projection of cleaning liquid
and/or compressed air when commanded by the user of the
vehicle.
[0118] The electronic control unit is configured, according to some
embodiments, to actuate the projection of cleaning liquid and
compressed air consecutively.
[0119] According to a particular embodiment, when the optical
sensor 13 detects the presence of soiling in its field of view
despite the centrifugal effect, the control unit may stop the
actuator 5 in order to haft the rotation of the optical element
9.
[0120] The electronic control unit then commands the projection of
cleaning liquid by the nozzle 22, in order to detach the soiling,
for example. The electronic control unit then commands the
projection of compressed air by the same nozzle 22 or by a second
nozzle, not shown here, in order to remove any soiling encrusted on
the optical element 9. The electronic control unit then reactivates
the actuator 5 to make the optical element 9 rotate again at a
given rotation speed, which may be higher or lower than the
rotation speed of the optical element 9 during the normal operation
of the protection device 3. The projection of compressed air may be
carried out before, simultaneously with, or after the restarting of
the rotation of the optical element 9 according to this
embodiment.
[0121] Advantageously, the protection device 3 comprises a
proximity sensor, not shown here, connected to the electronic
control unit. Such a proximity sensor may be, for example, a
capacitive proximity sensor. The capacitive proximity sensor is
configured to detect the approach of another object in the
proximity of the optical element 9. In such a case, the capacitive
proximity sensor transmits this information to the electronic
control unit, enabling the latter to command the automatic halting
of the actuator 5, in order to stop the rotation of the optical
element 9 if another object approaches. Thus the optical element 9
projecting from the bodywork part 2 cannot be damaged if it comes
into contact with an object as a result of its rotation,
particularly when the driving aid system 1 is to be installed at
the front or rear bumpers of the vehicle.
[0122] Optionally, it is also possible to provide elements for
limiting the noise of the motor, in order not to inconvenience the
passengers inside the vehicle or the other users when the
protection device 3 is used because of the high rotation speeds of
the actuator 5.
[0123] Optionally, the optical element 9 of the protection device 3
may also comprise an integrated de-icing or demisting system, such
as a de-icing filament or resistance for example, to ensure that
the driving aid system 1 operates correctly regardless of the
weather conditions.
[0124] Optionally, the optical element 9 of the protection device 3
may be coupled to a system (such as a piezoelectric transducer) for
causing this optical element 9 to vibrate, in order to prevent the
adhesion of soiling to the outer surface of this optical element
9.
[0125] These examples of embodiment are provided by way of
illustration and are not limiting. In fact, a person skilled in the
art may, without departing from the scope of the invention, replace
the actuator 5 described here with any other type of actuator that
may be used to make the optical element 9 rotate. Additionally, a
person skilled in the art may use a transparent optical element 9
with an outer surface having other properties that allow the
adhesion of the soiling to this outer surface to be limited without
departure from the scope of the present invention. Moreover, it is
entirely possible for a person skilled in the art, without
departure from the scope of the present invention, to use any type
of coupling means 7 to make the optical element 9 rotate, these
coupling means 7 possibly being mechanical or magnetic.
[0126] Thus, the fast and effective cleaning of an optical sensor
13, which may be a camera for example, designed to be fitted to a
motor vehicle, is possible because of the protection device 3 of
the present invention, which comprises a rotatably mounted optical
element 9 whose axis of rotation coincides with the optical axis 15
of the optical sensor 13. The rotation of the optical element
causes the soiling to be removed by the action of the centrifugal
force to which the soiling is subjected. The fact that the axis of
rotation of the optical element 9 coincides with the optical axis
15 of the optical sensor 13 enables this system to be adapted to
any type of camera designed to be integrated into bodywork parts 2
of a motor vehicle or installed on the outside of the vehicle,
while retaining a wide field of vision.
* * * * *